by Catalina Camia, USA TODAY

by Catalina Camia, USA TODAY

Public opinion polls tell us that there's growing support for same-sex marriage. GOP Sen. Rob Portman of Ohio is one such example, creating a stir when he said last week that he now endorses such unions.

Changing attitudes, however, are not sweeping Congress. Consider this from Sen. Saxby Chambliss, R-Ga.:

"I'm not gay. So I'm not going to marry one," Chambliss told Politico, when asked if his views had changed on same-sex marriage.

That view is highlighted in a new Pew Research Center poll, which says 28% of gay marriage supporters previously did not. The supporters who once were opponents often say their attitudes shifted because they know someone who is gay. Rising support from people born since 1980 also contributes to the increased support for same-sex marriage.

The Politico story in which Chambliss is quoted notes lawmakers in Congress are "changing their legislative tactics and toning down their public rhetoric - rather than undergoing a sea change in their stances."

Gay marriage is in the news a lot these days because the Supreme Court takes up the hot-button topic next week. More than 80 prominent Republicans signed onto a legal brief to the high court that says same-sex marriage is a constitutional right. Only two of them - Reps. Ileana Ros-Lehtinen of Florida and Richard Hanna of New York - are sitting members of Congress.